Protectors against marine growth in the form of water impervious envelopes complementary to the underwater shape of a vessel are known. Such envelopes after being positioned around the under body of the vessel are then filled with growth inhibiting liquids which may be only fresh water or water containing anti-fouling chemicals. The problem with such envelopes is that they are difficult to maneuver around the vessel's under body and various schemes have been resorted to to ease this task but no one system has been more efficacious than another and all have been burdensome.
The broad object of the present invention is to provide in combination with a boat slip a protector for an underwater body which is more easily maneuvered into and out of its position of use than in known systems.